Active Blobs

Fast, Reliable Head Tracking Under Varying Illumination

“…In our case the templates are computed in the texture map plane. A similar approach has been successfully used in [5,9,19].…”

“…Once we know the initial position of the model we can generate a collection of warping templates from the reference texture [9,13,19]. Given a parameter displacement matrix N a = n 1 n 2 : : : n D ] we compute the warping templates matrix B = b 1 b 2 : : : b K ] with columns: b k = T 0 ; ;(I 0 a 0 + n k ) (2) where I 0 is the initial frame of the sequence, n k is the parameter displacement vector for the k th difference vector (warping template), and a 0 is the initial warping parameter vector (i.e., the initial position and orientation of the cylinder).…”

Active Voodoo Dolls: A Vision Based Input Device for Nonrigid Control.

“…Furthermore, correlation-based methods are not well-suited to tracking moving objects that undergo scaling, rotation, or nonrigid deformation, since tracking is accomplished via correlation with a translating template. Larger deformations can be accomodated if the problem is posed in terms of deformable image registration [2,23]. In particular, La Cascia, et al [6], use this approach to register a texture-mapped polygonal model of a person's head with an incoming video sequence.…”

“…We model the region using the active blob formulation [23]. Tracking of the voodoo doll's deformation is modeled in terms of a deformable, triangular mesh that captures object shape plus a color texture map that captures object appearance.…”

“…We will now give an overview of the active blobs formulation. For a more detailed formulation, readers are refered to [23].…”